Bottle cap and bottle combination



United States Patent inventor William '1. Brady Indianapolis, Indiana Appl. N 0. 799,707

Filed Feb. 17, 1969 Patented Nov. 17, 1970 Assignee Bio-Dynamics Inc.

Indianapolil, Indiana a corporation of Indiana BOTTLE CAP AND BOTTLE COMBINATION 8 Claims, 5 Drawing Figs.

U.S. Cl 215/43, 220/39 lnt..Cl. 865d 41/04 Field of Search i. 215/43,

Primary Examiner-Raphael H. Schwartz Attorney-Woodard, Weikart, Emhardt and Naughton ABSTRACT: A bottle cap including an inner beaded tubular plug, a top wall and an outer tubular skirt having a screw thread on its inner wall. A frustoconical shaped section joins the top wall and the inner tubular plug, and along with the bead forms a seal on the inside of said bottle.

Patented Nov. 17, 1970 WILL/HM I BR/IDY BY Mm, a/M,M m m ATTORNEYS BACKGROUND OF THE INVENTION 1. Field ofthe Invention The field of the invention is containers.

2. Description of the Prior Art In many applications of bottles and closures, it is very important that the closure give a good seal with the bottle. For example, in cuvette bottles used also to contain reagents in medical testing kits, it is extremely important that the closure give a good seal or else the reagents may become contaminated or partially dissipated affecting the test results. Such cuvette bottles may be filled by automatic filling apparatus and may be closed by automatic capping apparatus. Whether or not the closure is effected manually or by automatic apparatus it is desirable that a good seal be obtained even though the cap is not completely screwed down on the bottle. In certain prior art arrangements it is necessary that the closure be screwed down through 95 to 100 percent of its travel to getany seal at all.

SUMMARY OF THE INVENTION One embodiment of the invention may include a screw cap closure for bottles having a cylindrical neck with a screw thread, said screwlcap closure comprising: a top wall; an inner tubular plug being relatively thin walled and resilient to conform to irregularities in the neck of said bottle and having a distal end and a proximal end; a bead formed on said plug adjacent the distal end thereof and extending around said plug member and adapted to engage the inside of said bottle; a frustoconical shaped section joining said top wall and said inner tubular plug, said frustoconical section having an outwardly facing sloping surface adapted to engage and seal with the inside of said bottle when the top is screwed down on the bottle; and an outer tubular skiirt having a screw thread on its inner wall adapted to threadedly engage the screw thread .on said bottle.

One object of this invention is to provide an improved screw cap.

Another object of this invention is to provide an improved screw cap bottle combination.

Still another object of this invention is to provide a screw cap bottle combination which provides a good seal even though not closed completely.

A further object of this invention is to provide a screw cap bottle combination which provides multiple seals when tightened down completely. I

Related objects and advantages will become apparent as the description proceeds.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a cross section through a bottle cap embodying the present invention.

FIG. 2 is a side elevation of a bottle in itself not novel but forming a part of the combination of the present invention.

FIG. 3 is a reduced top elevation of the bottle cap of FIG. 1.

FIG. 4 is a side elevation partially in section showing the bottle cap and bottle combination of the present invention.

FIG. 5 is an enlarged fragmentary view of a portion of the structure illustrated in FIG. 4 showing the bottle cap fully engaged with the bottle of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now more particularly to FIG. 1, there is illus- A frustoconical shaped section 20 joins the top wall 11 and the inner tubular plug 12. There is also provided an outer tu- Referring to FIG. 2, the bottle 15 is shown as having a cylindrical neck 30, with a screw thread 31 on the outside thereof, and a relatively smooth cylindrical surface 32 on the inside thereof which is rounded off at 35. The bottle 15 also has an upper smooth surface 36 which engages the top wall 11. The

bottle 15 also'has adjacent its neck 30 an enlarged portion 40 which acts as a stop preventing further tightening of the cap 10 downwardly on the threads of the bottle.

Referring to FIG. 4, the cap 10 is shown as screwed onto the neck 30 of the bottle. The rounded off portion 35 of the inside of the neck 30 is in contact with the outwardly facing sloping surface 41 of the frustoconically shaped section 20 of the cap. The bead 17 is in contact with the inside cylindrical surface 32 of the bottle 15. In the position of FIG. 4, a seal is provided by the bead l7 and by the surface 41 of the frustoconical portion 20 of the cap.

The cap may be further tightened down into the position of FIG. 5 to provide a more thorough seal. As can be seen from FIG. 5, the frustoconical section 20 and the top wall 11 of the cap are caused to bulge upwardly. This bulging is produced by the engagement of the top 36 of the bottle and the rounded surface 35 of the bottle with the top wall 11 and the frustoconical portion 20 of the cap. The head 17 still produces its seal on the inside of surface 32 of the bottle, but the seal produced at the top wall 11 and the frustoconical section 20 is more thorough than the seal produced in FIG. 4 and extends over a greater area. It will be noted in FIG. 5 that the enlarged portion 40 of the bottle acts as a stop and prevents further tightening down of the cap to a position which may pull the cap out of shape and destroy the cap.

The bead 17 which is of course formed of the same resilient material as the rest of the cap, has an outside diameter which in its nonstressed condition is of a greater diameter than the inside diameter of the neck surface 32. In one specific embodiment of the present invention the nonstressed outside diameter of the bead 17 is between .337 and .335 inches. In the same embodiment of the invention the inside diameter of the surface 32 is .315 inches minimum 1D. In the same embodiment of the invention, the outside diameter of the plug 12 is between .312 and .307 inches. The thickness of the wall of the plug 12 is .031 inches. While the configuration of the plug 12 is generally cylindrical in shape, the outer wall 50 does have somewhat of a taper which is at an angle of l and 30 minutes with the taper reducing the diameter of the wall 50 from the proximal end to the distal end thereof.

In the same embodiment of the invention, the outside diameter of the bottle 15 at the neck 30 and at the root 5] of the threads is .454 inches maximum. The inside diameter of the threads 22- at their most inwardly projecting portion is between .456 and .460 inches. The maximum diameter of the threads 31 of the bottle is between .499 and .514 inches, while the diameter of the deepest portion of the threads 22 in the cap is between .516 and .520 inches.

Thus the bottle 15 has an outside diameter at the roots of its threads which is less than the minimum diameter of the outer skirt at its threads. Also the bottle has an outside diameter at the top of its threads which is less than the corresponding diameter of the deepest portion of the threads in the skirt of the cap. Further, the bottle threads have a greater maximum diameter than the minimum diameter of the threads in the skirt of the cap.

It will be evident from the above description that the present invention provides an improved screw cap bottle combination which provides a good seal even though not completely closed. It will also be evident that the screw cap of the present invention provides multiple seals when tightened down to any extent. It has been found from actual test that the combination of the frustoconical portion 20 and the bead or O-ring seal '17 produce a much better sealing action than is produced by the bead l7 alone. Thus in one test the skirt 21 was cut away and the bottle with cap thereon placed in a vacuum. it was found that, when the surface 41 was in contact with the surface 35, 18 inches of Mercury vacuum was required to pop the cap out of the bottle. In contrast, with only the bead 17 in contact with the bottle and the surface 41 out of contact with the bottle only inches of Mercury vacuum was required to remove the cap.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention and the scope of the claims are also desired to be protected.

I claim:

1. A screw cap closure for bottles having a cylindrical neck with a screw thread, said screw cap closure comprising:

a. a top wall; a proximal b. an inner tubular plug being relatively thin walled and:

resilient to conform to irregularities in the neck of said bottle and having a distal end and a proximal end;

c. a bead formed on said plug adjacent the distal end thereof and extending around said plug, member and adapted to engage the inside of said bottle;

d. a frustoconical shaped section joining said top wall and said inner tubular plug, said frustoconical section having an outwardly facing sloping surface adapted to engage and seal with the inside of said bottle when the top is screwed down on the bottle; and

e. an outer tubular skirt having a screw thread on its inner wall adapted to threadedly engage the screw thread on saidbottle.

2. A screw cap bottle combination comprising:

a. a bottle having a cylindrical neck with a screw thread on the outside thereof and a relatively smooth rounded off cylindrical surface on the inside thereof;

b. a screw-cap including a top wall;

c.' an inner tubular plug being relatively thin walled and resilient to conform to irregularities in the neck of said bottle and having a distal end and a proximal end, said plug having an outside diameter which is less than the inside diameter of said neck surface, said plug being received within said neck;

d. a bead of resilient material formed on said plug adjacent the distal end thereof and extending around said plug member and in sealing engagement with said bottle, said bead having'a greater nonstressed outer diameter than the inside diameter of said neck surface; e. a frustoconical shaped section joining said top wall and said inner tubular plug, said frustoconical section having an outwardly facing sloping surface in sealing engagement with said bottle at said rounded off cylindrical surface; and an outer tubular skirt having a screw thread on its inner wall in threaded engagement with the screw thread on said bottle.

3. A screw cap bottle combination in accordance with claim 2 wherein said frustoconical shaped section engages said bottle inside rounded off cylindrical surface with sufficient force to cause said top wall and said frustoconical shaped section to bulge outwardly of said bottle.

4. A screwcap bottle combination in accordance with claim 2 wherein said bottle includes an enlarged portion adjacent to said neck, said outer tubular skirt engaging said enlarged portion which acts as a stop preventing further tightening of said cap downwardly on the threads of said bottle.

5. A screw cap bottle combination in accordance with claim 2 wherein said bottle has an outside diameter at the roots of its threads which is less than the minimum diameter of said outer skirt at it's'threads, said bottlehaving an outside diameter at the top of its threads which is less than the corresponding diameter of the deepest portion of said threads in said skirt, said bottle threads having a greater maximum diameter than the minimumdiameter of the threads in said skirt.

6. A screw cap bottle combination in accordance with claim 3 wherein said bottle includes an enlarged portion adjacent to said neck, said outer tubular skirt engaging said enlarged portion which acts as a stop preventing further tightening of said cap downwardly on the threads of said bottle.

7. A screw cap bottle combination in accordance with claim 4 wherein said bottle has an outside diameter at the roots of its threads which is less than the minimum diameter of said outer skirt at its threads, said bottle having an outside diameter at the top of its threads which is less than the corresponding diameter of the deepest portion of said threads in said skirt,

said bottle threads having a greater maximum diameter than the minimum diameter of the threads in said skirt.

8. A screw cap bottle combination in accordance with claim 7 wherein said skirt has a plurality of axially extending ridges thereon on the external surface thereof for assisting in rotating said cap. 

